/*
* Atmel AT91 SAM9 SoCs reset code
*
* Copyright (C) 2007 Atmel Corporation.
* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
* Copyright (C) 2014 Free Electrons
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <soc/at91/at91sam9_ddrsdr.h>
#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */
#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */
#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */
#define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */
#define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */
#define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */
#define AT91_SHDW_CPTWK0_(x) ((x) << 4)
#define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */
#define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */
#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */
#define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */
#define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */
#define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */
enum wakeup_type {
AT91_SHDW_WKMODE0_NONE = 0,
AT91_SHDW_WKMODE0_HIGH = 1,
AT91_SHDW_WKMODE0_LOW = 2,
AT91_SHDW_WKMODE0_ANYLEVEL = 3,
};
static const char *shdwc_wakeup_modes[] = {
[AT91_SHDW_WKMODE0_NONE] = "none",
[AT91_SHDW_WKMODE0_HIGH] = "high",
[AT91_SHDW_WKMODE0_LOW] = "low",
[AT91_SHDW_WKMODE0_ANYLEVEL] = "any",
};
static struct shdwc {
struct clk *sclk;
void __iomem *shdwc_base;
void __iomem *mpddrc_base;
} at91_shdwc;
static void __init at91_wakeup_status(struct platform_device *pdev)
{
const char *reason;
u32 reg = readl(at91_shdwc.shdwc_base + AT91_SHDW_SR);
/* Simple power-on, just bail out */
if (!reg)
return;
if (reg & AT91_SHDW_RTTWK)
reason = "RTT";
else if (reg & AT91_SHDW_RTCWK)
reason = "RTC";
else
reason = "unknown";
dev_info(&pdev->dev, "Wake-Up source: %s\n", reason);
}
static void at91_poweroff(void)
{
asm volatile(
/* Align to cache lines */
".balign 32\n\t"
/* Ensure AT91_SHDW_CR is in the TLB by reading it */
" ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
/* Power down SDRAM0 */
" tst %0, #0\n\t"
" beq 1f\n\t"
" str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
/* Shutdown CPU */
"1: str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
" b .\n\t"
:
: "r" (at91_shdwc.mpddrc_base),
"r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
"r" (at91_shdwc.shdwc_base),
"r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW)
: "r6");
}
static int at91_poweroff_get_wakeup_mode(struct device_node *np)
{
const char *pm;
unsigned int i;
int err;
err = of_property_read_string(np, "atmel,wakeup-mode", &pm);
if (err < 0)
return AT91_SHDW_WKMODE0_ANYLEVEL;
for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++)
if (!strcasecmp(pm, shdwc_wakeup_modes[i]))
return i;
return -ENODEV;
}
static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
int wakeup_mode;
u32 mode = 0, tmp;
wakeup_mode = at91_poweroff_get_wakeup_mode(np);
if (wakeup_mode < 0) {
dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n");
return;
}
if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) {
if (tmp > AT91_SHDW_CPTWK0_MAX) {
dev_warn(&pdev->dev,
"shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n",
tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX);
tmp = AT91_SHDW_CPTWK0_MAX;
}
mode |= AT91_SHDW_CPTWK0_(tmp);
}
if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
mode |= AT91_SHDW_RTCWKEN;
if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
mode |= AT91_SHDW_RTTWKEN;
writel(wakeup_mode | mode, at91_shdwc.shdwc_base + AT91_SHDW_MR);
}
static int __init at91_poweroff_probe(struct platform_device *pdev)
{
struct device_node *np;
u32 ddr_type;
int ret;
at91_shdwc.shdwc_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(at91_shdwc.shdwc_base))
return PTR_ERR(at91_shdwc.shdwc_base);
at91_shdwc.sclk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(at91_shdwc.sclk))
return PTR_ERR(at91_shdwc.sclk);
ret = clk_prepare_enable(at91_shdwc.sclk);
if (ret) {
dev_err(&pdev->dev, "Could not enable slow clock\n");
return ret;
}
at91_wakeup_status(pdev);
if (pdev->dev.of_node)
at91_poweroff_dt_set_wakeup_mode(pdev);
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
if (np) {
at91_shdwc.mpddrc_base = of_iomap(np, 0);
of_node_put(np);
if (!at91_shdwc.mpddrc_base) {
ret = -ENOMEM;
goto clk_disable;
}
ddr_type = readl(at91_shdwc.mpddrc_base + AT91_DDRSDRC_MDR) &
AT91_DDRSDRC_MD;
if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
iounmap(at91_shdwc.mpddrc_base);
at91_shdwc.mpddrc_base = NULL;
}
}
pm_power_off = at91_poweroff;
return 0;
clk_disable:
clk_disable_unprepare(at91_shdwc.sclk);
return ret;
}
static int __exit at91_poweroff_remove(struct platform_device *pdev)
{
if (pm_power_off == at91_poweroff)
pm_power_off = NULL;
if (at91_shdwc.mpddrc_base)
iounmap(at91_shdwc.mpddrc_base);
clk_disable_unprepare(at91_shdwc.sclk);
return 0;
}
static const struct of_device_id at91_poweroff_of_match[] = {
{ .compatible = "atmel,at91sam9260-shdwc", },
{ .compatible = "atmel,at91sam9rl-shdwc", },
{ .compatible = "atmel,at91sam9x5-shdwc", },
{ /*sentinel*/ }
};
MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
static struct platform_driver at91_poweroff_driver = {
.remove = __exit_p(at91_poweroff_remove),
.driver = {
.name = "at91-poweroff",
.of_match_table = at91_poweroff_of_match,
},
};
module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
MODULE_AUTHOR("Atmel Corporation");
MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");
MODULE_LICENSE("GPL v2");